Conduit pipe for telecommunication cable

ABSTRACT

A conduit pipe is installed within a cable tunnel and telecommunication cables are disposed in the conduit pipe. The conduit pipe is divided longitudinally into a plurality of divided bodies. Each divided body is equipped at one longitudinal side with a retaining part and at the other longitudinal side with a protruded part. A single conduit pipe is formed when the divided bodies are connected to each other along the longitudinal side. Since the divided bodies can be wound around a small-diameter bobbin to be carried, the space for their custody is reduced and the carriage thereof is easier. Further, since connection parts on surfaces of the conduit pipes can be arranged such that they occupy empty spaces between conduit pipes, the space occupied by the connection parts can be minimized, thereby comparatively larger number of telecommunication cables being able to be disposed within the cable tunnel.

FIELD OF THE INVENTION

The present invention relates to a conduit pipe for a telecommunicationcable; and, more particularly, to a conduit pipe which is dividedlongitudinally into a plurality of divided bodies for easy carriage andinstallation.

DESCRIPTION OF THE PRIOR ART

Conventionally a telecommunication cable is installed by takingfollowing steps: forming manholes with a predetermined distance, buryingan exterior pipe which is to function as a cable tunnel, installing aplurality of conduit pipes in the exterior pipe and arrangingtelecommunication cables within the conduit pipes.

FIG. 1 is a schematic drawing of a cable tunnel built by using aconventional method and FIG. 2 is a cross-sectional view of the cabletunnel with conventional conduit pipes installed therein. As shown inFIG. 1, manholes 1 and 1′ are disposed tens or hundreds of meters apartfrom each other, and a typical distance between two adjacent manholes is246 m. An exterior pipe 2 for building the cable tunnel is buriedbetween the manholes 1 and 1′. A plurality of conduit pipes 3 areinstalled within the exterior pipe 2. As illustrated in FIG. 2, atelecommunication cable 4 is laid within the conduit pipe. The exteriorpipe generally has a diameter big enough to accommodate some additionalconduit pipes 3 in case an increase of telecommunication cables isneeded later on.

Several types of PVC pipe such as foam conduit pipe have been utilizedto form the conduit pipe 3. The conduit pipe is formed by connecting aplurality of such PVC pipes whose lengths are approximately 6 m.However, since the conduit pipes having a length of 6 m cannot be putinto the cable tunnel through an opening of a manhole, the entirenumbers of conduit pipes that can be accommodated within the cabletunnel must be installed all together at the same time when the cabletunnel is built. Further, since the conduit pipes occupy a lot of space,it is difficult to carry a great number of pipes at a time. Stillfurther, connection parts of the conduit pipe 3 have larger diameterthan any other part thereof, thereby reducing the number of conduitpipes to be installed within the cable tunnel. As a result, the numberof communication cables 4 that can be arranged within the conduit pipes3 is decreased as well.

In the case of using a PE pipe instead of a PVC pipe as a conduit pipe,comparatively larger number of conduit pipes may be installed in a cabletunnel because the PE pipe has no connection part. However, the PE pipegenerally has a diameter of 100 mm, and thus it is difficult to carrythe PE pipes because the diameter of a bobbin becomes excessivelyenlarged when the PE pipes are wound.

THE SUMMARY OF THE INVENTION

It is, therefore, the object of the present invention to provide aconduit pipe offering an effective use of an inner space of a cabletunnel. The conduit pipe is made of soft materials and longitudinallydivided into a plurality of divided bodies which are kept disconnectedat the time of conveyance and then assembled at the time ofinstallation.

In accordance with an aspect of the present invention, there is provideda conduit pipe a plurality of which are installed within a cable tunneland within which telecommunication cables are built. The conduit pipecomprises a plurality of divided bodies to be connected to form a singleconduit pipe, wherein each divided body is equipped at one longitudinalside with retaining parts and at the other longitudinal side withprotruded parts.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and features of the present invention willbecome apparent from the following description of a preferred embodimentgiven with reference to the accompanying drawings, in which:

FIG. 1 is a schematic drawing showing a cable tunnel built by using aconventional method;

FIG. 2 provides a cross-sectional view of conventional conduit pipesinstalled within a cable tunnel;

FIG. 3 sets forth a perspective view of a conduit pipe in accordancewith the present invention;

FIG. 4 describes an axial cross-sectional view of the conduit pipe inFIG. 3;

FIG. 5 depicts an enlarged view of part B in FIG. 4 showing a disengagedstate thereof; and

FIG. 6 is a cross-sectional view of the conduit pipes installed within acable tunnel in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The followings are descriptions of a preferred embodiment of the presentinvention with reference to the accompanying drawings.

FIG. 3 is a perspective view of a conduit pipe in accordance with thepresent invention and FIG. 4 represents an axial cross section of theconduit pipe of FIG. 3. FIG. 5 is an enlarged view of part B in FIG.4and offers a disengaged state thereof. FIG. 6 is a cross-sectional viewof conduit pipes of the present invention installed within a cabletunnel.

In accordance with the preferred embodiment of the present invention, aconduit pipe 20 comprises a plurality of divided bodies 22 that are madeby dividing the conduit pipe 20 longitudinally. The divided bodies 22have preferably the same length as a standard distance between manholes,e.g. 246 m. As shown in FIG. 3, the conduit pipe 20 is spilt into threedivided bodies 22 which are angularly symmetrical to each other. Eachdivided body 22 has a retaining part 30 along one longitudinal side anda protruded part 40 along the other longitudinal side. The protrudedpart 40 is equipped with a saw-toothed protrusion 42, and the retainingpart 30 is equipped with a saw-toothed groove 32 which engages with thesaw-toothed protrusion 42 formed on the protruded part 40 of anotherdivided bodies of the conduit pipe 20.

By configuring the conduit pipe as cited above, when a plurality ofconduit pipes are arranged, connection parts, which are formed byengaging the protruded part of one divided body with the retaining partof another divided body and projected on the surface of conduit pipes,are arranged such that they occupy empty spaces between conduit pipes,thereby minimizing space occupied by the connection parts. The number ofdivided bodies of a conduit pipe may be varied depending on thematerials used for manufacturing the divided bodies and the timerequired for installation thereof. Divided bodies may be angularlyunsymmetrical to each other.

In accordance with the preferred embodiment of the present invention, aconduit pipe having a circular cross section is formed when threedivided bodies 22 are connected. For establishing firm connection, it ispreferable to construct connection parts of the divided bodies 22 by theabove-described method. However, any configuration of the connectionparts may be adopted if it can minimize the connection parts on thesurfaces of the conduit pipes.

The divided bodies 22 are preferably made of polyethylene pipe. Whensoft materials are applied for constructing the conduit pipe, it becomespossible to wind the conduit pipe on a bobbin, thereby reducing thespace needed for storage, which also makes it easier to install anyadditional conduit pipes within the exterior pipe even after theinstallation of an exterior pipe 10 is already completed.

A method for installing a conduit pipe of the present inventioncomprises following steps: the divided bodies 22 of the conduit pipe 20are wound around a bobbin to be carried. At an installation site, thedivided bodies 22 are unwound from the bobbin and connected to eachother. The connection process can begin by fitting a protruded part 40of a divided body 22 into a retaining part of another divided body 22and making a saw-toothed protrusion 42 engage with a saw-toothed groove32. Following these steps, three divided bodies 22 are jointed and aconduit pipe 20 having a circular cross section is formed. After theconnection is established, the conduit pipe 20 is put into the exteriorpipe 10 to be installed therein. Since the conduit pipe 20 is made ofvery soft materials, when the addition of the conduit pipe 20 isrequired even after the installation of the cable tunnel is completed,it is possible to assemble the conduit pipe 20 first and then insert itthrough the mouth of manholes 1 and 1′ into the exterior pipe 10.

In the preferred embodiment of the present invention, connection partsof the conduit pipe 20 are arranged such that they occupy empty spacesbetween conduit pipes. Thus, the space occupied by connection parts ofthe conduit pipe is reduced, thereby enabling more conduit pipes to beinstalled within the exterior pipe 10 functioning as a cable tunnel.Further, since the conduit pipe 20 can be wound around a bobbin having asmall diameter, the conduit pipe 20 can be easily carried and alsodoesn't need much space for storage. Accordingly, the costs involvingstorage and carriage can be lowered. Besides, all the conduit pipes 20that can be accommodated within a cable tunnel need not be installed allat once when the cable tunnel is constructed. Any conduit pipe can beinstalled individually when additional installation is required, thusresulting in a cost-cut with regard to materials and construction.

While the present invention has been described with respect to theparticular embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the spirit and scope of the invention as defined in the followingclaims.

What is claimed is:
 1. A conduit pipe installed within a cable tunneland having communication cables disposed therein, comprising a pluralityof divided bodies to be connected to form the conduit pipe, each dividedbody including a retaining part at one longitudinal side and a protrudedpart at the other longitudinal side, wherein each divided body is madeof a soft material such that each divided body is windable around abobbin while being stored or carried and is flexible to such a degreethat the conduit pipe formed by connecting the divided bodies isinstallable in the cable tunnel through a manhole.
 2. The conduit pipeof claim 1, wherein the protruded part has a saw-toothed protrusion andthe retaining part has a saw-toothed groove to be engaged with thesaw-toothed protrusion.
 3. The conduit pipe of claim 1, wherein thedivided bodies are made of soft polyethylene.
 4. The conduit pipe ofclaim 1, wherein the divided bodies are angularly symmetrical to eachother.
 5. The conduit pipe of claim 4, wherein the divided bodies areangularly symmetrical to each other with an opening angle of a degree of120.
 6. A conduit pipe assembly for a conduit pipe of the sort throughwhich communication cables are carried underground between manholecovers, the conduit pipe assembly comprising: at least three dividedbodies connectable along longitudinal sides thereof, each divided bodyincluding a retaining part at one longitudinal side and a protruded partat the other longitudinal side; wherein the divided bodies areadjustable between a disassembled state in which each divided body iswound on a bobbin, and an assembled state in which the divided bodiesare assembled into said conduit pipe.
 7. The conduit pipe assembly ofclaim 6, wherein the conduit pipe is formed from soft polyethylene. 8.The conduit pipe assembly of claim 6 in the assembled state, incombination with a plurality of communication cables accommodated in theconduit pipe.
 9. The conduit pipe assembly of claim 8 in the assembledstate, wherein the conduit pipe and the communication cables both extendfor at least 246 meters.
 10. The conduit pipe of claim 8 in theassembled state, wherein the conduit pipe and the communication cablesboth extend underground between two manholes.
 11. A communicationassembly comprising: a conduit pipe assembly for a conduit pipe of thesort through which communication cables are carried underground betweenmanhole covers, the conduit pipe assembly comprising: at least threedivided bodies connectable along longitudinal sides thereof, eachdivided body including a retaining part at one longitudinal side and aprotruded part at the other longitudinal side; wherein the dividedbodies are adjustable between a disassembled state in which each dividedbody is wound on a bobbin, and an assembled state in which the dividedbodies are assembled into said conduit pipe; and a plurality ofcommunication cables accommodated within the conduit pipe, when theconduit pipe assembly is in the assembled state.
 12. The communicationassembly of claim 11, wherein the conduit pipe is formed from softpolyethylene.
 13. The communication assembly of claim 11 with theconduit pipe assembly in the assembled state, wherein the conduit pipeand the communication cables extend between two manholes.
 14. Thecommunication assembly of claim 11 with the conduit pipe assembly in theassembled state, wherein the conduit pipe and the communication cablesboth extend for at least 246 meters.